There are two built-in interactive functions to help a user track down a library that is within the
load-path -- i.e.,
locate-library [to see the path] and
find-library [to open the library in a buffer].
locate-library is an interactive compiled Lisp function in 'subr.el'.
(locate-library LIBRARY &optional NOSUFFIX PATH INTERACTIVE-CALL)
Show the precise file name of Emacs library LIBRARY.
LIBRARY should be a relative file name of the library, a string.
It can omit the suffix (a.k.a. file-name extension) if NOSUFFIX is
nil (which is the default, see below).
This command searches the directories in 'load-path' like 'M-x load-library'
to find the file that 'M-x load-library RET LIBRARY RET' would load.
Optional second arg NOSUFFIX non-nil means don't add suffixes 'load-suffixes'
to the specified name LIBRARY.
If the optional third arg PATH is specified, that list of directories
is used instead of 'load-path'.
When called from a program, the file name is normally returned as a
string. When run interactively, the argument INTERACTIVE-CALL is t,
and the file name is displayed in the echo area.
find-library is an interactive autoloaded compiled Lisp function in
Find the Emacs Lisp source of LIBRARY.
LIBRARY should be a string (the name of the library).